Read full article – http://speckyboy.com/2009/04/13/22-firefox-extensions-to-turn-gmail-into-a-powerhouse-of-productivity-and-manageability/

Gmail is perhaps the greatest web app ever developed, it is very popular (over 100 million users), has a generous 2GB of free storage (a small percentage of users will ever use more than this), and very, very user friendly. It is certainly powerful, but is it powerful enough? With Firefox Addons you can take your inbox even further…

Campaign Monitor – http://www.campaignmonitor.com/

Constant Contact – http://www.constantcontact.com/